Pictures from on set show them laughing and embracing, with Minogue wearing denim overalls of the sort beloved by her character and Donovan sporting a check shirt and jeans.
Feisty mechanic Charlene was often seen wearing the practical outfit and it became her calling card among fans.
A second image shows them leaning against the bonnet of a car, with Donovan kissing his on-screen lover on the forehead.
Minogue shared the images with her 2.4 million Instagram followers and wrote: “Now we’re back together.”
Donovan, meanwhile, posted a photo of the street sign for Ramsay Street signed by him and his co-star, as well as a snap of the cover of his script.
He wrote: “So good to be back with this absolute legend @kylieminogue.”
It is ceasing production after failing to secure new funding since being dropped by its broadcaster earlier this year.
Donovan and Minogue, who are both 54, played Scott and Charlene until their departures in 1989 and 1988 respectively.
Their wedding episode was watched by more than two million Australian viewers when it first aired in 1987, and later pulled in an audience of almost 20 million when it was shown in the UK in 1988.
The soap also launched the careers of Hollywood stars such as Margot Robbie and Liam Hemsworth.
Memento star Guy Pearce, who started his career playing Mike Young in the soap, is also reprising his role for the finale.
Joining them will be Peter O’Brien, who appeared in the show’s first episode as Shane Ramsay, as well as Ian Smith, who played Harold Bishop, Mark Little, who played Joe Mangel, and Paul Keane, who played Des Clarke.
– Neighbours will end with a double-episode special on Channel 5 at 9pm on July 29.